Compacted muriate of potash fertilizers containing micronutrients and methods of making same

ABSTRACT

A granular cohered MOP fertilizer having one or more micronutrients, and one or more binding ingredients. The fertilizer is prepared by compacting MOP feed material with one or more micronutrients and one or more optional binders to form a cohered MOP composition. The cohered MOP composition is then further processed, such as by crushing and sizing, to form a cohered granular MOP product containing micronutrients. The process yields a fertilizer product containing micronutrients with superior elemental and granule size distribution without comprising handling or storage qualities.

RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication No. 61/514,952 filed Aug. 4, 2011, which is incorporatedherein in its entirety by reference.

FIELD OF THE INVENTION

The invention relates generally to fertilizer compositions. Morespecifically, the invention relates to the entrainment of micronutrientsinto muriate of potash fertilizers via compaction processes.

BACKGROUND OF THE INVENTION

Essential plant nutrients include primary nutrients, secondary ormacronutrients, and trace or micronutrients. Primary nutrients includecarbon, hydrogen, oxygen, nitrogen, phosphorous, and potassium. Carbonand oxygen are absorbed from the air, while other nutrients includingwater (source of hydrogen), nitrogen, phosphorous, and potassium areobtained from the soil. Fertilizers containing sources of nitrogen,phosphorous, and/or potassium are used to supplement soils that arelacking in these nutrients.

According to the conventional fertilizer standards, the chemical makeupor analysis of fertilizers is expressed in percentages (by weight) ofthe essential primary nutrients nitrogen, phosphorous, and potassium.More specifically, when expressing the fertilizer formula, the firstfigure represents the percent of nitrogen expressed on the elementalbasis as “total nitrogen” (N), the second figure represent the percentof phosphorous expressed on the oxide basis as “available phosphoricacid” (P₂O₅), and the third figure represents the percent of potassiumalso expressed on the oxide basis as “available potassium oxide” (K₂0),or otherwise known as the expression (N—P₂O₅—K₂O).

Even though the phosphorous and potassium amounts are expressed in theiroxide forms, there is no P₂0₅ or K₂0 in fertilizers. Phosphorus existsmost commonly as monocalcium phosphate, but also occurs as other calciumor ammonium phosphates. Potassium is ordinarily in the form of potassiumchloride or sulfate. Conversions from the oxide forms of P and K to theelemental expression (N—P—K) can be made using the following formulas:%P=%P₂0₅×0.437%K=%K₂0×0.826%%P₂0₅=%P×2.29%K₂0=%K×1.21

Muriate of potash (MOP), otherwise known as potassium chloride, KCl, isan agricultural fertilizer, and is the most common source of fertilizerpotassium. MOP by definition contains 48% to 62% soluble K₂O, mainly aschloride. MOP is typically extracted from naturally occurringunderground mineral sources either by conventional mining or solutionmining techniques. Once extracted, MOP can be processed into a number ofdifferent finished forms or KCl products suitable for specificindustrial, chemical, human or animal nutrients or agriculturalapplications as desired by individual customers.

Finished MOP, for the purpose of agricultural consumption, is typicallysold in a granular form. The purity and granule size may vary dependingon the end use to which the product will be put. The granules areproduced using crushing and sizing processes known to one of ordinaryskill in the art, such as by compaction and the subsequent crushing andsizing which thereby break up the larger pieces of MOP into smallergranules. Compaction implies the continuous rolling of MOP feed materialat elevated pressures yielding cohesion of material in the resultantproduct. The grading of MOP, and hence its market value, is alsodependent on both the purity and granule size of the product. Typicallythe MOP is screened to the desired particle size for a particular need.

A typical MOP feed stock has a granule size that is comparable to tablesalt, which is less than the desired granule size. In order to obtainlarger granules, this feedstock is first compacted using a compactingprocess such as a simple roll compacter or the like to produce asheet-like cohered product. Subsequent processing typically involvescontrolled breakage of the MOP sheet into granules, which are thensorted to a desired size range by screening or other classificationmethods known in the industry. A non-limiting example of a standardindustry known roll compactor is K.R. Komarek's B220B Compactor (or anyof the “B” models or high pressure briquetting and compacting machines)available from K.R. Komarek, Inc. of Wood Dale, Ill.

In addition to the primary nutrients, such as potassium that is madeavailable to plants via the MOP fertilizer added to soil, micronutrientsand secondary nutrients are also essential for plant growth. These arerequired in much smaller amounts than those of the primary nutrients.Secondary nutrients can include, but are not limited to, sulfur (SO₄),calcium (Ca), magnesium (Mg) or combinations thereof. Micronutrients caninclude, but are not limited to, for example, boron (B), zinc (Zn),manganese (Mn), nickel (Ni), molybdenum (Mo), copper (Cu), iron (Fe),chlorine (Cl), or combinations thereof. From this point forward andthroughout the specification, for the sake of simplicity, the term“micronutrient” refers to and includes both secondary nutrients andmicronutrients.

A common method of micronutrient application for crops is soilapplication. Recommended application rates usually are less than 10lb/acre on an elemental basis. Separate micronutrient applications atthese low rates are difficult and are prone to result in the pooruniformity of distribution. Including micronutrients with mixedfertilizers is a convenient method of application and some methods allowmore uniform distribution with conventional application equipment. Costsalso are reduced by eliminating a separate application step. Fourmethods of applying micronutrients with mixed fertilizers can includeincorporation during manufacture, bulk blending with granularfertilizers, coating onto granular fertilizers and seeds, and mixingwith liquid herbicides or fluid fertilizers.

Bulk blending with granular fertilizers is the practice of bulk blendingmicronutrient compounds with phosphate, nitrogen and potash fertilizers.The main advantage to this practice is that fertilizer grades can beproduced which will provide the recommended micronutrient rates for agiven field at the usual fertilizer application rates. The maindisadvantage is that segregation of nutrients can occur during theblending operation and with subsequent handling. Micronutrients areoften small in particle size which can result in segregation in a bulkblend. In order to reduce or prevent size segregation during handlingand transport, the ideal micronutrient granules must be close to thesame size as the phosphate, nitrogen and potash granules. Because themicronutrients are required in very small amounts for plant nutrition,this practice has resulted in granules of micronutrients unevenlydistributed and generally too far from most of the plants to be ofimmediate benefit as most micronutrient elements migrate in soilsolution only a few millimeters during an entire growing season.

Coatings decrease the possibility of segregation. However, some surfacebinding materials are unsatisfactory because they do not maintain themicronutrient coatings during bagging, storage, and handling, whichresults in segregation of the micronutrient sources from the granularfertilizer components.

Steps have been taken to reduce the segregation problem for example asin the case of sulfur or sulfur platelets in the fertilizer portion asdescribed in U.S. Pat. No. 6,544,313 entitled “Sulfur-ContainingFertilizer Composition and Method for Preparing Same” and in the case ofmicronutrients as described in U.S. Pat. No. 7,497,891 entitled, “Methodfor Producing a Fertilizer with Micronutrients,” both of which areincorporated by reference in their entireties. This preparation method,however, is directed to a granulation process.

Some micronutrient pelletizing and compaction applications exist in suchproducts as sodium chloride (salt) and kieserite (magnesium sulfatemonohydrate); however the inclusion of micronutrients into a primarynutrient, such as MOP, using a roll compactor is not known in the priorart to the inventors' knowledge.

Micronutrient addition has historically been performed in downstreamoperations outside the processing boundaries of MOP miners and millers.There is a well-documented long term need to increase crops yields inorder to feed an ever-increasing world population. Therefore, thereremains a need to economically create a compacted, crushed and sized,granular MOP value-added fertilizer product that contains one or moremicronutrients that maximizes the introduction of the micronutrient(s)into soil solution and ultimately to the root zone of plants.

SUMMARY OF THE INVENTION

Embodiments of the invention include a cohered granular MOP fertilizerhaving one or more micronutrients, such as, but not limited to, boron(B), zinc (Zn), manganese (Mn), molybdenum (Mo), nickel (Ni), copper(Cu), iron (Fe), chlorine (Cl), sulfur (S) in its elemental form, sulfurin its oxidized sulfate form (SO₄) and combinations thereof at variousconcentrations. The fertilizer can also include a compaction aid,coloring agent, and/or one or more binding ingredients such as sodiumhexametaphosphate (SHMP). Micronutrients, when compacted into MOP remainsoluble and dissolve readily when applied using standard fertilizerpractices.

According to embodiments of the invention, the fertilizer is prepared bycompacting MOP feed material with one or more micronutrients and one ormore optional binders to form a cohered MOP product. The cohered MOPproduct is then further processed, such as by crushing and sizing, toform a cohered granular MOP product containing micronutrients. Theprocess yields a fertilizer product containing micronutrients withsuperior or more uniform elemental and granule size distribution,without compromising handling or storage qualities, compared to theaforementioned micronutrient applications. The uniformity ofdistribution of a fertilizer containing micronutrients compared toexisting methods of dry application allow individual plants betteraccess to the nutrients.

The above summary of the invention is not intended to describe eachillustrated embodiment or every implementation of the present invention.The detailed description that follows more particularly exemplifiesthese embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the process flow sheet for the injection of micronutrientsinto an MOP feed.

FIG. 2 is a graph displaying breakage results of Hersey 0-0-62 MOP(based on N—P₂O₅—K₂O) plus Micronutrient (HM) samples.

FIG. 3 is a graph displaying Production Yields of Carlsbad 0-0-60 MOP(based on N—P₂O₅—K₂O) plus micronutrient test product MOP using Sulfur.

FIG. 4 is a graph displaying Production Yields of Carlsbad 0-0-60 MOP(based on N—P₂O₅—K₂O) plus micronutrient test product MOP usingMolybdenum.

FIG. 5 is a graph displaying Breakage results of Carlsbad 0-0-60 MOP(based on N—P₂O₅—K₂O) plus micronutrient test product MOP.

FIG. 6 is a graph displaying Dust results of Carlsbad 0-0-60 MOP (basedon N—P₂O₅—K₂O) plus micronutrient test product MOP products.

FIG. 7 is a graph displaying Moisture Absorption results of Carlsbad0-0-60 MOP (based on N—P₂O₅—K₂O) plus micronutrient test product MOP.

FIG. 8 is a picture of Final Carlsbad 0-0-60 MOP (based on N—P₂O₅—K₂O)plus micronutrient test product MOP.

FIG. 9 is an Energy-Dispersive X-ray Spectroscope (EDS) spectrum of asample of a granule of compacted MOP containing micronutrients accordingto an embodiment of the invention.

FIG. 10 is a Scanning Electron Microscope (SEM) micrograph of the sampleof FIG. 9.

FIG. 11A is an EDS map of chlorine of the SEM of FIG. 10.

FIG. 11B is an EDS map of potassium of the SEM of FIG. 10.

FIG. 11C is an EDS map of manganese of the SEM of FIG. 10.

FIG. 11D is an EDS map of sodium of the SEM of FIG. 10.

FIG. 11E is an EDS map of zinc of the SEM of FIG. 10.

FIG. 11F is an EDS map of oxygen of the SEM of FIG. 10.

FIG. 11G is an EDS map of sulfur of the SEM of FIG. 10.

FIG. 12A is an EDS spectrum of a sample of a crushed granule ofcompacted MOP containing micronutrients according to an embodiment ofthe invention.

FIG. 12B is an EDS spectrum of a sample of the full granule of compactedMOP containing micronutrients of FIG. 12A.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

A cohered fertilizer granular product according to embodiments of theinvention generally includes a MOP fertilizer base and one or moremicronutrients (or secondary nutrients), including, but not limited to,boron (B), zinc (Zn), manganese (Mn), molybdenum (Mo), nickel (Ni),copper (Cu), iron (Fe), chlorine (Cl), sulfur (S) in its elemental form,sulfur in its oxidized sulfate form (SO₄), or combinations thereof atvarious concentrations. As discussed above, the term “micronutrients”refers to and includes both secondary nutrients and micronutrients. Theconcentration of one or more micronutrients can range from about 0.001to about 99.99 weight percent and more particularly from about 0.001 toabout 10 weight percent.

The MOP fertilizer base can be any of a variety of commerciallyavailable MOP sources, such as, but not limited to, for example, an MOPfeed material having a K₂O content (on the N—P₂O₅K_(x)O scale) rangingfrom about 20 weight percent to about 80 weight percent. In oneparticular non-limiting example, the chemical analysis of the MOP feedmaterial is 0-0-60 wt %; in another non-limiting example, the chemicalanalysis of the MOP feed material is 0-0-62 wt %, and in yet anothernon-limiting example, the chemical analysis of the MOP feed material is0-0-55 wt %.

The fertilizer can also include one or more binding agents oringredients in order to improve the strength or handling ability of thefinished compacted granular MOP product so that the granules are lesslikely to wear or break down during handling or transport, as describedin U.S. Pat. No. 7,727,501, entitled “Compacted granular potassiumchloride, and method and apparatus for production of same,” incorporatedherein by reference in its entirety. A binding agent is a chemical thatis added into the feed of a compaction circuit to improve the strengthand quality of compacted particles. The binding agent acts to sequesteror chelate impurities in the MOP feedstock, while providing adhesiveproperties to the compacted blend. Binding agents can include, forexample, sodium hexametaphosphate (SHMP), tetra-sodium pyrophosphate(TSPP), tetra-potassium pyrophosphate (TKPP); sodium tri-polyphosphate(STPP); di-ammonium phosphate (DAP), mono-ammonium phosphate (MAP),granular mono-ammonium phosphate (GMAP), potassium silicate, sodiumsilicate, starch, dextran, lignosulfonate, bentonite, montmorillonite,kaolin, or combinations thereof. Accordingly, an effective amount of thebinding agent, such as SHMP, is added to a potassium chloride feedstockto produce a blended potassium chloride product with improved handling,transport and storage capabilities is in the range from 100 ppm to 1500ppm, preferably in the range from 300 ppm to 1000 ppm, and morepreferably in the range from 500 ppm to 800 ppm. In addition to oralternatively to the binding agents, some of the micronutrientsthemselves can act as binding agents to improve particle strength.

According to one embodiment of the invention, a cohered granular MOPfertilizer containing micronutrients is made by blending one or moremicronutrients into the MOP feed of a compaction circuit. Themicronutrients can be added to the feed in advance of compaction. Thecompaction of this blended MOP feed stock and then conventional furtherprocessing, such as crushing and sizing, yields cohered MOP fertilizergranules containing micronutrients that are evenly distributedthroughout the granular product.

A production line or production circuit for producing compacted granularMOP generally includes a material feed apparatus such as a beltconveyor, pneumatic conveyor or the like which input various particulateMOP streams, screenings, recovered or discarded MOP material, one ormore micronutrients, and one or more optional binding agents to acompactor. The compactor then presses the feed material at elevatedpressure into a cohered MOP intermediate sheet or cake, which can thenbe crushed, classified, resized, or otherwise refinished into a desiredfinished MOP product.

FIG. 1 is a flow chart illustrating the steps involved in onecontemplated embodiment of the method of production of the presentinvention. Specifically, FIG. 1 shows the injection of a micronutrientinto the MOP feed of a production circuit. The micronutrient(s) can beadded to the MOP feed material at various locations in the circuit by aninjector including metering equipment to allow more precise control ofthe amounts of each component added per unit of MOP feedstock.

After addition of the micronutrient(s) and optionally binding agent(s)to the MOP feed material, the additives and MOP feed material areblended. The blending step can either take place passively, by allowingthese materials to come together or blend during their joint carriagethrough the feed mechanism, or alternatively there may be specificblending equipment added to the MOP production circuit between theinjector and the compactor to provide more aggressive or active blendingof the micronutrient(s), optional binders, and MOP feedstock prior tocompaction.

The blended MOP feed material, now properly mixed with themicronutrients is then compacted. The compaction process can beperformed using conventional compaction equipment such as a rollcompactor or the like. The cohered intermediate yielded can then befurther processed into the desired finished granular product usingmethods such as crushing, screening or other conventional classificationmethods suitable to yield a finished product of the desired particlesize or type. These steps are also shown in the flow diagram of FIG. 1.

In one particular embodiment of the invention, it is desirable toincorporate more than one different micronutrient in combination, andthis could either be accomplished by the injection of a pre-blendedcombination of multiple micronutrients or else by the separate placementor injection of the desired amounts of the micronutrients into the MOP.It will be understood that any attendant process or equipmentmodifications to permit the addition of one or more micronutrientsand/or binding agents, either concurrently or separately, to the MOPfeedstock are contemplated within the scope of the present invention.

The following representative examples further define embodiments of thepresent invention.

Example 1

A number of MOP fertilizer compositions compacted with variousmicronutrients were produced and evaluated for technical feasibility.MOP feed material supplied by Mosaic Hersey Potash Mine of Michigan, USA(hereinafter “Mosaic Hersey”) was compacted with various micronutrientsat different concentrations. The chemical analysis of the MOP was 98.8%by weight of KCl, 1.1% by weight of sodium chloride (NaCl), 283 ppm ofcalcium (Ca), 11 ppm of iron (Fe), 59 ppm of magnesium (Mg), and 287 ppmof sulfate (SO₄). The total moisture content of the MOP feed was 0.1439%by weight. The MOP feed material supplied by Mosaic Hersey is a 0-0-62%K₂O product (expressed in terms of N—P₂O₅—K₂O) produced using solutionmining techniques. The MOP feed material is white in color as is theinherent nature of MOP produced from the solution mining technique.

The micronutrients used in the production of the Hersey Micronutrient(HM) samples (Table 1 below) included boron (in the form of anhydrousborax Na₂B₄O₇), zinc (in the form of zinc sulfate monohydrateZnSO₄.H₂O), zinc (in the form of zinc oxide ZnO), manganese (in the formof manganese sulfate MnSO₄.H₂O), and/or molybdenum (in the form ofsodium molybdate dehydrate Na₂MoO₄.2H₂O).

The following compositions were produced (hereinafter “the HMproducts”):

TABLE 1 Test Run Micronutrient Description Micro- nutrients SampleMicronutrient Compounds (%) HM3 Na₂B₄O₇ - anhydrous borax 0.5% B HM4Na₂B₄O₇ - anhydrous borax 0.7% B HM5 (#1) Na₂B₄O₇ - anhydrous borax -0.50% (#2) Na₂MoO₄•2H₂O - sodium molybdate B-0.03% Mo HM6 (#1) Na₂B₄O₇ -anhydrous borax - 0.70% (#2) Na₂MoO₄•2H₂O - sodium molybdate B-0.08% MoHM8 MnSO₄•H₂O - Manganous Sulphate monohydrate 1% Mn HM9 (#1)MnSO₄•H₂O - Manganous Sulphate 1.00% monohydrate - Mn-0.03% (#2)Na₂MoO₄•2H₂O - sodium molybdate Mo HM10 MnSO₄•H₂O - Manganous Sulphatemonohydrate 2% Mn HM11 Zinc Sulphate mono hydrate - ZnSO₄•H₂O 1% Zn HM12Zinc Oxide - ZnO 1% Zn HM13 (#1) Zinc Sulphate mono hydrate -ZnSO₄•H₂O - 1% Zn-1% (#2) MnSO₄•H₂O - Manganous sulphate Mn monohydrate

Each product was generated using the same process flow sheet: The MOPand micronutrient(s) were blended in a batch mixing drum. The blendedproduct was then delivered to the compaction circuit. The compactioncircuit used included a compactor producing a sinusoidal flake, a flakebreaker, a disintegrator (crusher) and a 2-deck vibratory screenproviding a 4×10 Tyler Mesh product. Oversized and undersized granuleswere recycled for further processing.

Samples from each of the HM products were analyzed for K₂O content by anoutside independent laboratory. Table 2 displays the Analytical Values(independent lab) vs. theoretical K₂O value (% Calc) based on thecontent of the micronutrient compound and the basis of a 62% K₂O MOPfeed.

TABLE 2 K₂O Analysis of the HM Products K2O K2O (%) (%) SampleMicronutrient Compounds Calc Analytical HM3 Na₂B₄O₇ - anhydrous borax60.3 60.2 HM4 Na₂B₄O₇ - anhydrous borax 59.6 59.48 HM5 (#1) Na₂B₄O₇ -anhydrous borax - 60.3 59.78 (#2) Na₂MoO₄•2H₂O - sodium molybdate HM6(#1) Na₂B₄O₇ - anhydrous borax - 59.5 59.43 (#2) Na₂MoO₄•2H₂O - sodiummolybdate HM8 MnSO₄•H₂O - Manganous Sulphate 59.8 59.41 monohydrate HM9(#1) MnSO₄•H₂O - Manganous Sulphate 59.7 59.54 monohydrate - (#2)Na₂MoO₄•2H₂O - sodium molybdate HM10 MnSO₄•H₂O - Manganous Sulphate 57.659.05 monohydrate HM11 Zinc Sulphate mono hydrate - ZnSO₄•H₂O 60 60.07HM12 Zinc Oxide - ZnO 61.1 61.23 HM13 (#1) Zinc Sulphate mono hydrate -57.8 57.91 ZnSO₄•H₂O - (#2) MnSO₄•H₂O - Manganous sulphate monohydrate

Samples from each of the HM products were analyzed for micronutrient(boron, molybdenum, manganese and zinc) content by an outsideindependent laboratory. The micronutrients found in anhydrous borax,molybdate, manganese sulphate monohydrate and zinc sulphate monohydrateare effectively entrained in a compacted granule.

Results are shown in Table 3.

TABLE 3 Micronutrients Analysis of the HM Products MicronutrientsMicronutrients Sample Micronutrient Compounds (%) Addition (%)Analytical HM3 Na₂B₄O₇ - anhydrous borax 0.5% B 0.537% B HM4 Na₂B₄O₇ -anhydrous borax 0.7% B 0.574% B HM5 (#1) Na₂B₄O₇ - anhydrous borax -0.50% B-0.03% Mo 0.551% B-0.017% Mo (#2) Na₂MoO₄•2H₂O - sodium molybdateHM6 (#1) Na₂B₄O₇ - anhydrous borax - 0.70% B-0.08% Mo 0.718% B-0.053% Mo(#2) Na₂MoO₄•2H₂O - sodium molybdate HM8 MnSO₄•H₂O - Manganous Sulphate1% Mn 1.01% Mn monohydrate HM9 (#1) MnSO₄•H₂O - Manganous Sulphate 1.00%Mn-0.03% 1.03% Mn-0.02% Mo monohydrate - Mo (#2) Na₂MoO₄•2H₂O - sodiummolybdate HM10 MnSO₄•H₂O - Manganous Sulphate 2% Mn 1.3% Mn monohydrateHM11 Zinc Sulphate mono hydrate - ZnSO₄•H₂O 1% Zn 0.93% Zn HM12 ZincOxide - ZnO 1% Zn 0.4% Zn HM13 (#1) Zinc Sulphate mono hydrate - 1.00%Zn-1.00% 0.89% Zn-0.95% Mn ZnSO₄•H₂O - Mn (#2) MnSO₄•H₂O - Manganoussulphate monohydrateQuality Metrics

Each of the HM products was screened in order to perform a sizeanalysis. Table 4 below displays standard fertilizer blending metricsincluding the Size Guide Number (SGN) and the Uniformity Index (UI) ofeach of the product streams along with a baseline. The formulas forthese sizing metrics are as follows:

-   -   SGN=d₅₀(μm)/10, or otherwise defined as the particle size in        millimeters of which 50% by weight of the sample is coarser and        50% finer times 100    -   UI=[d₅(μm)/1000)/(d₉₀(μm)/1000)]*100, or otherwise defined as        the particle size at which 95% of the material is retained,        divided by the particle size at which 10% of the material is        retained, multiplied by 100.

TABLE 4 SGN and UI of HM Products SGN UI Baseline 307 36 HM3 255 39 HM4289 34 HM5 282 36 HM6 275 35 HM8 278 36 HM9 269 36 HM10 288 43 HM11 26236 HM12 320 39 HM13 247 38

The SGN and UI for a baseline product (no micronutrient addition) is 307and 36 respectively. While the UI for the HM products is similar to thebaseline the SGN is smaller. The average SGN of the HM products is 271.

Two breakage procedures were performed to compare HM products with thebase line scenario. These were the conditioned and weathered breakagetests. The weathered breakage test is used to evaluate the hardness of aproduct that has been exposed to a relative humidity of 72% for 24hours. The conditioned breakage test is used to evaluate producthardness after 24 hours of exposure to 26% relative humidity. Thedifference between the conditioned and weathered breakage values isassumed to be the amount of weathering that took place.

A test sample for each HM product of the same or similar sieve analysiswas measured. For the weathered breakage test, the samples were exposedto the respective relative humidity for 24 hours. After a period ofshaking, the quantity of broken sample was measured, i.e. the % ofbreakage retained on a specified sized mesh screen.

FIG. 2 displays that each of the HM products has an improved weatheredbreakage value compared to baseline while conditioned breakage showsslightly higher values compared to baseline. Breakage values in FIG. 2do not indicate a concern for product quality; however they can bereduced if so desired using a binding agent.

In another series of breakage tests with Hersey's Ag-granular product,it was observed the breakage values could optionally be reduced to below10% at 700 ppm SHMP binder addition (Table 5).

TABLE 5 Breakage Results of Hersey Granular SHMP (ppm) 0 435 552 590 396584 716 Breakage % on 20 19.82 13.41 15.58 12.44 15.44 12.35 9.34 Mesh

Example 2

MOP feed material from Mosaic Carlsbad N. Mex. (also referred to asDyna-K) was compacted with various micronutrients and evaluated fortechnical feasibility. MOP from Carlsbad is generated using conventionalunderground mining techniques. The MOP generated from this process is a0-0-60% K₂O product (expressed in terms of N—P₂O₅—K₂O) and is red incolor as is the inherent nature of MOP produced from the undergroundmining technique.

The micronutrients added included 0.5 weight % boron (via 3.47 weight %Na₂B₄O₇.5H₂O), 1.0 weight % manganese (via 3.03% MnSO₇.H₂O), 1.0 weight% Zn (via 4.41 weight % ZnSO₄.7H₂O), 1.0 weight percent copper (via 4.10weight % CuSO₄.5H₂O), 1.0 weight % iron (via 4.98 weight percentFeSO₄.7H₂O), and 0.05 weight % molybdenum (via 0.13 weight %Na₂MoO₄.2H₂O). Each of the runs was repeated with the addition of 5weight % sulfur.

In the compaction method, initial ram pressures of 1000 psi and 2500psi, wherein 1000 psi ram pressure corresponds to about 20,000 psiapplied to the material being compacted, with the final product yields,i.e. percentage of actual final product compared to starting feedweight, being 51% and 75% respectively. It was noted that the dustlevels were visually lower with the higher ram pressure, which was usedfor the test runs.

The boron and boron/sulfur combination products ran well, yielding 67%and 60% respectively. There were no negative effects from the products,and the products flowed well with no equipment issues.

The manganese sulfate and manganese sulfate/sulfur combination productsresulted in a light negative effect on the feed screw with somestoppages, suggesting that the manganese had a binding effect on theforce feeder. The yields were 67% and 64% respectively.

The zinc compound of the zinc sulfate and zinc sulfate/sulfurcombination products has inherent surface moisture of about three toabout five percent. This moisture migrates to the feed, making the feedmoist which could potentially impact the flow rate in the hopper.However, the yields were not impacted, and the products demonstratedyields of 65% and 77% respectively.

The copper sulfate and copper sulfate/sulfur combination products wererequired different handling operations. While the copper had a damptexture, this moisture did not necessarily transfer to the feed uponmixing contrary to the observations with the zinc compound. The copperwas received in flake form (¼″ particles) that was pulverized beforebeing blended into the feed. The feed rates were lowered to reduce therisk of binding the flights of the feed auger. Blue particles wereobserved in the final product.

The combination of iron sulfate and sulfur impacted the activity of thefeed; however, the yields were higher when the iron compound was addedwithout sulfur. This is illustrated in the graph of FIG. 3.

The sodium molybdate and sodium molybdate/sulfur combination weretreated at two rates of 0.05 weight percent and 0.13 weight percent.Once the recycle came into the system, steady state was achieved and theyields increased and the run time surpassed normal operating time byabout twenty minutes compacting even dust which is normally rejected.This is illustrated by the graph in FIG. 4 which compares the yield ingrams of production to the test interval.

The sulfur compounds in general compacted into the MOP feed materialgenerally well, and the flake yield was generally increased slightly bythe addition of the sulfur.

The finished products were subjected to three quality tests includingdegradation (conditioned and weathered breakage), dusting tendency, andmoisture absorption properties, discussed in more detail below. The zincand zinc/sulfur products tended to have increased breakagecharacteristics, increased dusting, and increased moisture absorption ascompared to the standard MOP product. Breakage and dust values can befurther reduced if so desired using binding agents and alternatede-dusting treatment oils.

The iron and iron/sulfate products tended to turn black during moistureabsorption testing and emitted a strong odor of hydrogen sulfide. Thesulfur treated product generally had a lighter appearance than thenon-sulfur product having the same additive.

The weathered and conditioned breakages are illustrated in FIG. 5, thedusting results are illustrated in FIG. 6, and the moisture absorptionresults are illustrated in FIG. 7. A visual comparison of all productsis included in FIG. 8.

The moisture absorption test determines the critical relative humidityof a sample, which is defined as the relative humidity at which themoisture absorption of a sample sharply increases. The higher thecritical relative humidity of a product, the less moisture the productabsorbs thus maintaining better product integrity during handling andstorage. Specifically, the moisture absorption test determines theamount of moisture absorbed by a product (as a weight percent gained) atvarious points in time at various humidity settings, such as, forexample, 24 hours, 48 hours, and 72 hours when exposed to 26% relativehumidity (RH), 40% RH, 60% RH, 72% RH, 76% RH, 80% RH, 85% RH, and 100%RH.

The dusting results are from a de-dust test which is an abrasion testused to study the degradation characteristics of a sample. Productabrasion is created by tumbling the product for a period of time with anumber of steel balls. Air borne dust is drawn from the tumbler andweighed. The short term de-dust test is performed on samples that havebeen exposed to 40% RH for 24 hours, while the long term de-dust test isperformed on samples that have been exposed to seven days of 24 hourcycling between 26 and 72% RH.

Example 3

MOP feed supplied from Mosaic Potash Esterhazy K1 in Esterhazy,Saskatchewan, Canada (hereinafter “Mosaic K1” or “K1”) was compactedwith various micronutrients in two separate systems and evaluated fortechnical feasibility. This example documents the testing and resultsfrom testwork performed by a third party compaction tolling facility.The chemical analysis of the MOP is typically 96.25% by weight of KCl,2.87% by weight of sodium chloride (NaCl), 300 ppm of calcium (Ca), 300ppm of magnesium (Mg), and 600 ppm of sulfate (SO₄). The total moisturecontent of the MOP feed is typically 0.02% by weight at 130° C. The MOPfeed supplied from Mosaic K1 is a 0-0-60% K2O product (expressed interms of N—P₂O₅—K₂O) and is generated using conventional undergroundmining techniques. The MOP generated from this process is red/pink incolor as is the inherent nature of MOP produced from the undergroundmining technique.

The micronutrients used in this production of the K1 Micronutrient (EM)samples (Table 6 below) included boron (in the form of anhydrous boraxNa₂B₄O₇), zinc (in the form of zinc sulfate monohydrate ZnSO₄.H₂O), andmanganese (in the form of manganese Sulfate monohydrate MnSO₄.H₂O).

The following compositions were produced (hereinafter “the EMproducts”):

TABLE 6 Test Run Micronutrient Description Micronutrients SampleMicronutrient Compounds (%) EM-1 Na₂B₄O₇ - anhydrous borax 0.5% B EM-2ZnSO₄•H₂O - zinc sulfate monohydrate 1% Zn EM-3 (#1) MnSO₄•H₂O -manganese 1% Mn-1% Zn sulfate monohydrate - (#2) ZnSO₄•H₂O - zincsulfate monohydrate EM-4 (#1) MnSO₄•H₂O - manganese 2% Mn-1% Zn sulfatemonohydrate - (#2) ZnSO₄•H₂O - zinc sulfate monohydrate EM-5 MnSO₄•H₂O -manganese sulfate monohydrate 1% Mn EM-6 MnSO₄•H₂O - manganese sulfatemonohydrate 2% Mn

Each of these products was generated using the same process flow sheet(FIG. 1). The MOP and micronutrient(s) were blended in a batch mixingdrum. The blended product was then heated and delivered to thecompaction circuit. The compaction circuit consisted of a compactorproducing a sinusoidal flake, a flake breaker, a disintegrator and atwo-deck vibratory screen providing a 4×10 Tyler Mesh product. In thiscircuit, oversized and undersized particles were recycled for furtherprocessing.

In the compaction method, a ram pressure of 1000 psi was used, wherein1000 psi ram pressure corresponds to approximately 20,000 psi applied tothe material being compacted. Product yields ranged from 29.3% to 34.4%.There were no negative effects on production parameters from themicronutrient products, and the products flowed well with no equipmentissues.

Samples from each of the EM products were analyzed for micronutrient(boron, zinc and manganese) content by an outside independentlaboratory. The micronutrients found in anhydrous borax, manganesesulfate monohydrate and zinc sulfate monohydrate are effectivelyentrained in a compacted granule.

Results are shown in Table 7.

TABLE 7 Micronutrients Analysis of the EM Products MicronutrientsMicronutrients Sample Micronutrient Compounds (%) Addition (%)Analytical EM-1₁ Na₂B₄O₇ - anhydrous borax 0.5% B 0.46% B EM-1₂Na₂B₄O₇ - anhydrous borax 0.5% B 0.41% B EM-2₁ ZnSO₄•H₂O - zinc sulfatemonohydrate 1% Zn 0.67% Zn EM-2₂ ZnSO₄•H₂O - zinc sulfate monohydrate 1%Zn 0.45% Zn EM-3 (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 1%Mn-1% Zn 0.79% Mn-0.69% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate ZnEM-4 (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 2% Mn-1% Zn 1.77%Mn-0.76% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-5 MnSO₄•H₂O -manganese sulfate monohydrate 1% Mn 0.85% Mn EM-6 MnSO₄•H₂O - manganesesulfate monohydrate 2% Mn 1.62% MnSome adjustments to the dust removal systems may be required as smallersize micronutrients may be taken out with the dust. Each of the EMproducts was screened in order to perform a size analysis. Table 8 belowdisplays the Size Guide Number (SGN) and the Uniformity Index (UI) ofeach of the product streams along with a baseline.

TABLE 8 SGN and UI of EM Products SGN UI Baseline₁ 292 42 Baseline₂ 28041 EM-1₁ 293 43 EM-1₂ 270 43 EM-2₁ 289 43 EM-2₂ 294 41 EM-3 283 42 EM-4277 43 EM-5 277 43 EM-6 252 41

The SGN and UI for the baseline products (no micronutrient addition)were 292/280 and 42/41 respectively. While the UI for the EM products issimilar to the baseline, there is some variation with the SGN values.The average SGN of the EM products is 279. By maintaining the SGN and UIat acceptable levels, less segregation is generated, resulting in betterdistribution of the micronutrients in the field and increasedaccessibility of micronutrients to each plant.

The finished products were treated with de-dust oil and subjected toinitial and long term dusting tendency tests for quality purposes. Thedust percentage results are displayed below in Table 9.

TABLE 9 Initial & Long Term Dust Results of EM Products Initial DustLong Term Dust (%) (%) Baseline 0.0535 0.1534 EM-1 0.1010 0.1865 EM-20.0330 0.0330 EM-3 0.1101 0.1120 EM-4 0.1760 0.2280 EM-5 0.1490 0.1260EM-6 0.1480 0.2400

It was observed that from these tests, the addition of zinc only (EM-2)improved the dusting values from the baseline but did absorb moremoisture during the cycling period of this test and product was visuallynoted to be setting up during the experimental process. Manganesecombinations with Zinc (EM-3 and EM-4) did not exhibit such hygroscopicproperties. Meanwhile the addition of boron (EM-1) produced more dusts(particularly in the long term), while the remainder of the samples(which all contain manganese) showed the poorest results in terms ofboth initial and long term dusts. However, although some dust values maybe higher than desired, they can be reduced if so desired using bindingagents and alternate dedusting treatment oils.

Example 4

MOP feed supplied from Mosaic Potash Esterhazy K1 in Esterhazy,Saskatchewan, Canada (hereinafter “Mosaic K1” or “K1”) was compactedwith various micronutrients in two separate systems and evaluated fortechnical feasibility. This example documents the testing and resultsfor plant scale testwork performed at the Mosaic K1 facility. Again, thechemical analysis of the MOP is typically 96.25% by weight of KCl, 2.87%by weight of sodium chloride (NaCl), 300 ppm of calcium (Ca), 300 ppm ofmagnesium (Mg), and 600 ppm of sulfate (SO₄). The total moisture contentof the MOP feed is typically 0.02% by weight at 130° C. The MOP feedsupplied from Mosaic K1 is a 0-0-60% K2O product (expressed in terms ofN—P₂O₅—K₂O) and is generated using conventional underground miningtechniques. The MOP generated from this process is red/pink in color asis the inherent nature of MOP produced from the underground miningtechnique.

The micronutrients used in this production of the K1 Micronutrient (EM)samples (Table 10 below) included zinc (in the form of zinc sulfatemonohydrate ZnSO₄.H₂O), and manganese (in the form of manganese sulfateMnSO₄.H₂O).

The following compositions were produced (hereinafter “the EMproducts”):

TABLE 10 Test Run Micronutrient Description Micronutrients SampleMicronutrients (%) EM-4 (#1) MnSO₄•H₂O - manganese 2% Mn-1% Zn sulfatemonohydrate - (#2) ZnSO₄•H₂O - zinc sulfate monohydrate

During manufacture, two micronutrients were transported from bins in twoseparate augers controlled by variable frequency drives. These augersfed a mixing screw conveyor which mixed the two micronutrients withpre-heated MOP and delivered the mixture into the compaction system. Thecompaction circuit consisted of a compactor producing a sinusoidalflake, a flake breaker, a crusher and a two-deck vibratory screenproviding a 4×8 or 4×9 Tyler Mesh product. In this circuit, oversizedand undersized granules were recycled for further processing. Thiscircuit also used a finishing/polishing screen that provided a 4.5×8Tyler Mesh product.

Eleven samples of the EM-4 product were analyzed for micronutrient (zincand manganese) content by an outside independent laboratory. The zincand manganese micronutrients were found to be entrained in a compactedgranule.

Results are shown in Table 11.

TABLE 11 Micronutrients Analysis of the EM Products MicronutrientsMicronutrients Sample Micronutrient Compounds (%) Addition (%)Analytical EM-4₁ (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 2%Mn-1% Zn 1.45% Mn-0.79% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate ZnEM-4₂ (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 2% Mn-1% Zn 2.03%Mn-1.01% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₃ (#1)MnSO₄•H₂O - manganese sulfate monohydrate - 2% Mn-1% Zn 1.89% Mn-0.99%(#2) ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₄ (#1) MnSO₄•H₂O -manganese sulfate monohydrate - 2% Mn-1% Zn 1.93% Mn-1.06% (#2)ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₅ (#1) MnSO₄•H₂O - manganesesulfate monohydrate - 2% Mn-1% Zn 1.54% Mn-0.85% (#2) ZnSO₄•H₂O - zincsulfate monohydrate Zn EM-4₆ (#1) MnSO₄•H₂O - manganese sulfatemonohydrate - 2% Mn-1% Zn 1.50% Mn-0.85% (#2) ZnSO₄•H₂O - zinc sulfatemonohydrate Zn EM-4₇ (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 2%Mn-1% Zn 1.85% Mn-0.97% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate ZnEM-4₈ (#1) MnSO₄•H₂O - manganese sulfate monohydrate - 2% Mn-1% Zn 1.83%Mn-0.95% (#2) ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₉ (#1)MnSO₄•H₂O - manganese sulfate monohydrate - 2% Mn-1% Zn 1.60% Mn-0.87%(#2) ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₁₀ (#1) MnSO₄•H₂O -manganese sulfate monohydrate - 2% Mn-1% Zn 1.83% Mn-0.96% (#2)ZnSO₄•H₂O - zinc sulfate monohydrate Zn EM-4₁₁ (#1) MnSO₄•H₂O -manganese sulfate monohydrate - 2% Mn-1% Zn 1.03% Mn-0.57% (#2)ZnSO₄•H₂O - zinc sulfate monohydrate Zn

Again there are differences between the concentrations of micronutrientsadded and those in the final product. Additional adjustments can be doneto the dust removal systems as it is believed that micronutrients may beescaping the system with the dust losses. Additionally or alternatively,the micronutrients may have to be over formulated to ensure targetconcentrations are met.

Seven samples of the EM-4 product were screened in order to perform asize analysis. Table 12 below displays the Size Guide Number (SGN) andthe Uniformity Index (UI) of each of the product streams along with abaseline.

TABLE 12 SGN and UI of EM Products SGN UI EM-4₁ 307 56 EM-4₂ 302 55EM-4₃ 294 50 EM-4₄ 291 56 EM-4₅ 315 56 EM-4₆ 295 56 EM-4₇ 284 56

The typical SGN and UI for the baseline product (no micronutrientaddition) are 300 and 50 respectively. Results show a properly sizedcohered granular particle that is suitable for blending or directapplication in order to get even distribution of micronutrientcomponents in the field.

Nine samples of the finished EM-4 product were subjected to qualitytesting including degradation (breakage) and moisture absorptionproperties. The results of both tests can be observed below in Table 13.

TABLE 13 Quality Test Results for EM-4 Products Moisture % (Ranges0-0.10%) Breakage % EM-4₁ 0.05 12.0 EM-4₂ 0.05 11.5 EM-4₃ 0.07 11.8EM-4₄ 0.06 10.5 EM-4₅ 0.05 12.1 EM-4₆ 0.05 12.1 EM-4₇ 0.06 11.4 EM-4₈0.05 11.2 EM-4₉ 0.06 11.6

Results indicate moisture and product breakage are not significantlyimpacted after the micronutrients have been entrained into eachfertilizer particle.

Scanning Electron Microscope and Energy-Dispersive X-Ray Spectroscope

Referring to FIGS. 9-12B, four samples of the cohered granular MOP EMfertilizer products containing micronutrients from Example 4 were run onthe Scanning Electron Microscope (SEM) and Energy-Dispersive X-raySpectroscope (EDS) at an independent, outside laboratory. Samples wereanalyzed to determine the relative proportions and distributions of eachelement of interest within an individual granule and ensure evendistribution of the micronutrients with each cohered MOP+ micronutrientparticle. One of these samples was then crushed and scanned again tocompare the results to the scans obtained from the same sample ingranular form. Images were gathered for each sample then analyzed by theEDS to first produce a spectrum identifying the distribution of thecomponents potassium (K), chlorine (Cl), sodium (Na), zinc (Zn),manganese (Mn), sulfur (S), and oxygen (O) and then creating a visualmap of each element on the SEM image. The micrographs and EDS scan areshown in FIGS. 9-12B.

An EDS scan of an SEM image can determine the presence of an element andcan provide an idea of the relative proportion of the elements in asample, although quantitative results cannot be determined by EDS. Itshould be noted that zinc in its Zn2+ state (added as ZnSO4) emits alower-energy response which reads at the same energy level as theresponse generated from Na. Since the samples of Granular MOP containingmicronutrients are expected to have both Na and Zn2+, it cannot bedetermined which element is responsible for the peaks read on thespectra. All results labeled Zn and Na should therefore be considered asa composite of Zn and Na.

Referring to FIGS. 9 and 11A-F, all five samples showed consistentresults and contained all likely components without any significantamount of unexpected elements. From the EDS results shown in FIGS. 9 and11A-F, it can be seen that the expected high proportions of K and Cl. Asmentioned previously, the responses labeled “Zn” and Na” should beconsidered together to show the presence of Zn and Na. However, sinceboth Zn and Mn are added in sulfate (SO4) form, the EDS maps of O and S(FIGS. 11F and 11G) can be compared to the EDS map of Mn (FIG. 11B) tosee that there are areas where S and O are present where there is not aresponse from Mn. By this comparison, it is reasonable to deduce thatthese sulfate responses are due to the zinc sulfate.

As illustrated in the maps of FIGS. 11A-11F, the distribution ofcomponents, specifically Zn and Mn, is fairly even with only small areasof higher concentration of approximately ≦100 μm in size. Since there isagreement in the values of the crushed and granular forms of the samesample (see FIGS. 12A-12B) it can be inferred that the distribution ofthe components is likely uniform throughout the sample.

During the scanning, a quick overview of the entire sample was completedand confirmed that there were no large deposits (i.e. full granule)visible in the sample sub-sets.

Results from the SEM and EDS scans confirm that distribution andrelative proportions of the constituents of the Granular MOP containingmicronutrient are uniform and consistent among samples. The distributionof the manganese and sulfates can be confirmed with good confidence andcan be used to suggest the distribution of zinc. Uniform distribution ofmicronutrients within each granule results in better distribution of themicronutrients in the field and greater availability of micronutrientsto each plant.

The invention may be embodied in other specific forms without departingfrom the essential attributes thereof; therefore, the illustratedembodiments should be considered in all respects as illustrative and notrestrictive.

What is claimed is:
 1. A cohered muriate of potash (MOP) productcontaining one or more secondary and/or micronutrients, the MOP productbeing formed from a compacted MOP composition, the compositioncomprising: muriate of potash containing from about 48.0 weight percentto about 62.0 weight percent K₂O; and sodium tetraborate present in anamount such that the MOP product comprises a boron content between 0.001and 1.0 weight percent, wherein the MOP product exhibits a weatheredbreakage value and a conditioned breakage value of 10% or less.
 2. TheMOP product of claim 1, wherein the MOP product comprises a plurality ofcohered MOP granules formed from crushing and size classifying thecompacted MOP composition.
 3. The MOP product of claim 2, wherein thesodium tetraborate is distributed throughout each of the cohered MOPproduct, thereby being adapted to provide a uniform application ofmicronutrients to a growing area to facilitate greater access ofmicronutrients to a root zone of a plant in the growing area compared touncompacted dry blends.
 4. The MOP product of claim 2, wherein theplurality of cohered MOP granules has a substantially uniform sizedistribution to reduce or eliminate segregation during material handlingand transfer otherwise due to size migration of granules.
 5. The MOPproduct of claim 1, wherein the muriate of potash has a chemical profilerange of 0-0-48 weight percent K₂O to 0-0-62 weight percent K₂O based ona N—P₂O₅—K₂O convention.
 6. The MOP product of claim 5, wherein themuriate of potash has a chemical profile of 0-0-60 weight percent K₂Obased on the N—P₂O₅—K₂O convention.
 7. The MOP product of claim 5,wherein the muriate of potash has a chemical profile of 0-0-62 weightpercent K₂O based on the N—P₂O₅—K₂O convention.
 8. The MOP product ofclaim 1, wherein the at least one micronutrient or secondary nutrientsource provides one or more micronutrients selected from the groupconsisting of boron (B), zinc (Zn), manganese (Mn), molybdenum (Mo),nickel (Ni), iron (Fe) copper (Cu), sulfur (S) in its elemental form,sulfur in its oxidized sulfate form (SO₄), and combinations thereof. 9.The MOP product of claim 1, further comprising a source of amicronutrient or secondary nutrient, wherein the source of micronutrientor secondary nutrient provides one or more micronutrients and/orsecondary nutrients present in the composition in a range from about0.001 to about 10 weight percent.
 10. The MOP product of claim 1, thecomposition further comprising a binding agent.
 11. The MOP product ofclaim 10, wherein the binding agent is selected from the groupconsisting of sodium hexametaphosphate (SHMP), tetra-sodiumpyrophosphate (TSPP), tetra-potassium pyrophosphate (TKPP), sodiumtri-polyphosphate (STPP); di-ammonium phosphate (DAP), mono-ammoniumphosphate (MAP), granular mono-ammonium phosphate (GMAP), potassiumsilicate, sodium silicate, starch, dextran, lignosulfonate, bentonite,montmorillonite, kaolin, and combinations thereof.
 12. A method ofproducing a cohered muriate of potash (MOP) product containingmicronutrients comprising: providing an MOP composition includingmuriate of potash containing from about 48.0 weight percent to about62.0 weight percent K₂O, and at least one micronutrient source;compacting the MOP composition to form a compacted MOP composition;crushing the MOP composition into granules to produce the cohered MOPproduct, wherein the at least one micronutrient source comprises sodiumtetraborate present in an amount such that the MOP product comprises aboron content between 0.001 and 1.0 weight percent, wherein the MOPproduct exhibits a weathered breakage value and a conditioned breakagevalue of 10% or less.
 13. The method of claim 12, further comprising:classifying the granules of cohered MOP product by size.
 14. The methodof claim 13, wherein a size distribution of the granules issubstantially uniform, and wherein granules that are non-conforming areresized until conformance.
 15. The method of claim 12, wherein the atleast one micronutrient source further provides one or moremicronutrients selected from the group consisting of boron (B), zinc(Zn), manganese (Mn), molybdenum (Mo), nickel (Ni), copper (Cu), sulfur(S) in its elemental form, sulfur in its oxidized sulfate form (SO₄),and combinations thereof.
 16. The method of claim 12, wherein providingan MOP composition includes providing a plurality of micronutrientsources to the muriate of potash, each of the micronutrient sourcesbeing added separately and blended before compaction.
 17. The method ofclaim 12, wherein providing an MOP composition includes providing aplurality of micronutrient sources to the muriate of potash, themicronutrient sources being blended in bulk before addition into themuriate of potash.
 18. The method of claim 12, further comprising addinga binding agent to the MOP composition before compaction.
 19. The methodof claim 18, wherein the binding agent is selected from the groupconsisting of sodium hexametaphosphate (SHMP), tetra-sodiumpyrophosphate (TSPP), tetra-potassium pyrophosphate (TKPP), sodiumtri-polyphosphate (STPP); di-ammonium phosphate (DAP), mono-ammoniumphosphate (MAP), granular mono-ammonium phosphate (GMAP), potassiumsilicate, sodium silicate, starch, dextran, lignosulfonate, bentonite,montmorillonite, kaolin, and combinations thereof.
 20. The method ofclaim 12, further comprising: adding a second of a micronutrient orsecondary nutrient, wherein the second provides one or moremicronutrients or secondary nutrients present in the composition in arange from about 0.001 to about 10 weight percent.
 21. A cohered muriateof potash (MOP) product containing one or more secondary and/ormicronutrients, the MOP product being formed from a compacted MOPcomposition, the composition comprising: muriate of potash containingfrom about 48.0 weight percent to about 62.0 weight percent K₂O; atleast one micronutrient or secondary nutrient source; and aphosphate-containing binding agent present in an amount from 100 ppm to1500 ppm, and selected from the group consisting of sodiumhexametaphosphate (SHMP), tetra-sodium pyrophosphate (TSPP),tetra-potassium pyrophosphate (TKPP), sodium tri-polyphosphate (STPP);di-ammonium phosphate (DAP), mono-ammonium phosphate (MAP), andcombinations thereof.